Recording device



May 25, 1965 w. H. BUSSEY ETAL 3,185,998

RECORDING DEVICE 3 Sheets-Sheet 1 Filed Feb. 11, 1965 R m; 5 W3 4 WUT rm m w H H ms N mm wA J/ZM May 25, 1965 w. BUSSEY ETAL RECORDING DEVICE Filed Feb. 11, 1963 3 Sheets-Sheet 2 PEN 4| PEN RESERVOIR 6 7 2 r gum 42 I Y 68 INTERMlTTENT MA\N PUMP INK DRNE RESERVOIR.

Mdaa, W;

May 25, 1965 w. H. BUSSEY ETAL 3,185,998

RECORDING DEVICE Filed Feb. 11 1963 3 heet h 3 INVENTORS WILLIAM H. BUSSEY ALVIN a. Gum-ER, J'R.

UnitedStates Patent 3,185,998 RECORDING DEVICE William H. Busscy and Alvin G. Gunter, Jr., Rockford, Ill., assignors to Peter G. S. Mero, Evanston, Ill. Filed Feb. 11, 1963, Ser. No. 257,472 8 Claims. (Cl. 346-440) This invention relates to recording devices and more particularly to new and improved ink feed system for recording devices used in graphic communication recorders.

In graphic communication systems messages, sketches, or other data transcribed upon a writing surface at one station or the system are automatically reproduced at a second station in the system. Usually, the initial transcription is accomplished manually. The transmitter includes suitable apparatus for analyzing movements of a transmitter stylus or similar recording device and for developing electrical control signals representative of those movements. These signals are transmitted to and control the operation of a receiver recorder. A preferred system of this general kind is described in United States Patent No. 2,583,535 to Robert Adler, issued January 29, 1959, and in United States Patent No. 2,649,503 to Robert Adler, issued August 18, 1953. In such graphic communication systems, it is also necessary to provide a means for periodically replacing the recording medium, which is usually a continuous paper web but may constitute individual sheets of paper or other suitable material. A control signal is also transmitted to the receiver 7 to control the paper-feeding operation at the receiver, a paper teed control apparatus of this kind being described and claimed in Patent No. 2,621,249 to T. I. Ress, issued December 9, 1952.

In many instances, it is desirable to use a liquid ink recording arrangement at the transmitter or receiver of a graphic communication system of the kind described briefly hereinabove. Control of the ink supply, however, may present substantial problems. This is particularly true if the recording operation entails substantial vertical movement of the recording pen. Thus, if the pen is moved upwardly relative to an initial starting position, and a gravity feed arrangement is used for the ink, there may be an insufficient supply of ink available at the upper limit of the pen movement. On the other hand, a downward movement of the pen may cause flooding of the recording surface. Similar problems may be encountered with lateral movement of the pen due to the acceleration forces involved. Thus, skipping and flooding, where a liquid ink supply is employed, may lead to substantial illegibility of the recorded message, the problems being most acute where the recording surface is disposed in a substantially vertical plane, or at least at a substantial angle to the horizontal.

One system for alleviating this problem is described in the co-pending application of Walter I. Zenner, Serial No. 165,504, filed January 11, 1962, now Patent No. 3,116,- 964, issued January 7, 1964, in which an auxiliary ink reservoir is mounted on the pen arm for movement with the pen. In the Zenner system, ink is supplied to this auxiliary reservoir each time there is an interruption or" operation to feed a fresh sheet of paper into recording position. The ink supply for the pen is then derived directly from the auxiliary reservoir. The present invention is directed to an improvement and modification of the Zenner system, affording a more positive control of the supply of ink maintained in the auxiliary reservoir and also protecting the system against accumulation of ink solids in the auxiliary reservoir.

It is a principal object of the present invention, therefore, to provide a substantially constant supply of fresh 3,185,998 Patented May 25, 1965 ink in an auxiliary reservoir mounted upon the pen of a graphic communication system recorder.

A more specific object of the invention is to recirculate ink, intermittently, between a main reservoir and an auxiliary pen-carried ink reservoir, in a graphic communication system recorder, to prevent solidification or other deterioration of the ink in the auxiliary reservoir.

Another object of the invention is to provide positive control of the quantity of ink available in an auxiliary ink reservoir attached to and movable with the pen of a graphic communication system recorder.

A related object of the invention is to aflord an ink supply system for a graphic communication system recorder that provides a positive pumping action to convey ink from the main supply to an auxiliary reservoir and back again in a recirculation arrangement.

A specific object of the invention is to provide an inexpensive positive-action pump that may include two or more channels, is small and light in weight, yet affords a positive displacement action over a long period of operation.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art Without departing from the present invention in the purview of the appended claims.

In the drawings:

FIG. 1 is a front elevation view of a graphic communication system recorder including an ink supply system constructed in accordance with one embodiment of the present invention;

FIG. 2 is a side elevation view, partially cut away, of the recorder of FIG. 1;

FIG. 3 is a simplified block diagram of the ink supply system of the present invention;

FIG. 4 is a sectional elevation view of the pen in the graphic communication recorder of FIG. 1;

FIG. 5 is a detail view taken approximately as indicated by line 5-5 in FIG. 4;

FIG. 6 is a detail sectional view of a pump incorporated in the graphic communication recorder of FIGS. 1 and 2; and

FIG. 7 is a sectional view taken approximately as indicated by line 7-7 in FIG. 6.

The graphic communication recorder 10 illustrated in FIGS. 1 and 2 comprises a base member 11 that is provided with a plurality of upwardly projecting bosses 12 (see FIG. 2). Each of the bosses 12 receives a threaded support member 13, and a base plate 14 is mounted upon support member 13. The base plate 24 is utilized to support the paper feed mechanism and the platen of the recorder 10. A shaft 17 is mounted in suitable brackets (not shown) afiixed to lower end of base plate 14. A pair of sprocket wheels 21 and 22 are aflixed to shaft 17 and a paper guide roller 23 is mounted on the shaft between the two sprockets. Members 21, 22 and 23 are all afiixed to shaft 17 for rotation therewith. At the upper end of the recorder 10, a second shaft 25 is suitably mounted on the base plate 14; shaft 25 carries a further pair of sprocket wheels 26 and 27 and a paper guide roller 28. Sprockets 26 and 27 are aligned with sprockets 22 and 21, respectively, at the sides of the machine.

Afirst drive belt 29 is mounted upon sprockets 21 and 27 and a similar drive belt is provided at the opposite side of the machine in engagement with sprockets 22 and 26. The two belts preferably are each provided with a plurality of drive pins 31, as shown on belt 29.

The right-hand end of shaft 17 (FIG. 1) is extended and has mounted thereon a gear 35. Gear 35 is engaged by a worm gear 36 mounted upon the shaft 37 of a paper feed drive motor 38. Suitable means are provided, in recorder 16, for energizing motor 33 to drive shaft 17 through gears 35 and 36 when it is desired to advance paper through the recorder, as described more fully hereinafter. The control circuits for actuating motor 33 may be entirely conventional and may, for example, correspond to the paper feed control in the aforementioned Ress Patent No. 2,621,249. Accordingly, the control circuit has not been illustrated in the drawingsl Recorder 16 further includes a recording pen 41 that is mounted upon an elongated support member 42. Support member 42 is operatively connected to a pair of pen motors 43 and 44 by means of a drive linkage generally designated by reference numeral 45. Linkage 45 preferably is constructed in accordance with the construction shown in Adler Patent No. 2,583,535.

For a recording operation, a paper Web 47 is inserted into recorder 11) along a shelf 43 below support member 14 (see FIG. 2) and is brought into engagement with the pins 31 on the two drive belts near the point where the drive belts are engaged by sprockets 21 and 22. The paper web is carried upwardly along the drive belts and across a platen 48 that is approximately level with the drive belts and extends therebetween (see FIG. 1). The end of the paper web extends outwardly of the recorder beyond the upper sprockets 26 and 27, as shown in both FIGS. 1 and 2. To hold the paper tight and flat across platen 48, a U-shaped guide member 51 may be incorporated in the recorder. Guide member 51 presses the paper down against the belts to maintain the paper flat against the surface of the recording base or platen 43.

During a recording operation, pen motors 43 and 44 are energized, by signals received from a transmitter, to move support arm 42 and pen 41 across platen 48 and inscribe a message on the paper Web 47 covering the platen. When a given message, drawings, or the like has been recorded and a new recording sheet is desired, motor 38 is energized by suitable paper-feed signals from the transmitting station. The paper feed motor remains energized long enough to advance the paper feed belts, and hence paper strip 47, through a length sufficient to clear the previously recorded message from the platen and to afford a new recording sheet on the platen.

As thus far described, graphic communication recorder is constructed in accordance with the teachings of the aforementioned Adler and Ress patents, with a paper feed mechanism corresponding to that described and claimed in the co-pending application of Walter J. Zenner, Serial No. 132,691, filed August 21, 1961, now Patent No. 3,114,- 490, issued December 17, 1963. Accordingly, the foregoing brief description of operation should be adequate to indicate the basic functional attributes of the recorder.

The ink supply system to the present invention comprises a small reservoir 61, referred to hereinafter as an auxiliary ink reservoir. Auxiliary ink reservoir 61 is mounted upon support member 42 at the end thereof immediately adjacent pen 41. Preferably, auxiliary ink reservoir 61 is located a short distance below the outlet end of pen 41 to prevent flooding of the recording surface. Ink reservoir 61 is connected to pen 41 by a relatively short U-shaped ink supply line comprising an inlet portion 62 within reservoir 61, a reverse bend 63, and a connecting portion 64 that connects to the lower end of pen 41 as best shown in FIG. 4.

The ink supply system further includes a main ink reservoir 66 that may be mounted on recorder 10 at any desired position. That is, there is no requirement that the main ink supply 66 be disposed above or below pen 41 or at any particular lateral location with respect there to. In the present instance, reservoir 66 is disposed at the ri ht-hand side of the machine, as seen in FIG. 1, but this location is given only by way of example and can be changed to suit the space requirements of the particular recorder construction.

' The main ink reservoir 66 is connected to auxiliary reservoir 61 by two conduits. The first conduit comprises an inlet line and includes an initial section 67 connected to reservoir 66, a continuing section 68 extending through a pump 80, and a further conduit section 69 that is carried along one arm of the pen linkage and along pen support arm 42, terminating in the lower end of auxiliary ink reservoir 61 as best shown in FIGS. 1 and 4.

The second line connecting the two reservoirs is a recirculation line. The recirculation line starts with an intake opening 71 in the upper end of auxiliary reservoir 61 (FIGS. 4 and 5). The recirculation line continues with a section 72 that is extended along support member 42 and along one of the transverse members of linkage 45 and up to pump 80. The recirculation line further includes a section 73 extending through pump and is completed by a connecting section 74 that extends back into the main ink reservoir 66.

Auxiliary reservoir 61 is provided with a vent opening 76 at the upper end thereof. Opening 76 should be at an elevation greater than the intake opening 71 of the recirculation line of the ink system.

Pump 86 is mounted upon an extension of shaft 25, as shown in FIGS. 1, 6 and 7. The pump includes a cylindrical housing 81 that is symmetrical with respect to the axis of shaft 25. As shown in FIGS. 6 and 7, the two flexible tubing sections 68 and 73 of the ink inlet line and ink recirculation line, respectively, extend into cylindrical pump housing 81 and into engagement with a substantial circumferential portion of the inner surface of the housing. In the illustrated construction, flexible tubes 68 and 73 are in engagement with approximately a 180 segment of the inner surface of housing 81.

At the end of shaft 25 that projects into pump housing 86, a pumping member 83 is mounted on the shaft. Pumping member 63 is of circular external configuration, but is eccentric with respect to the axis of the shaft 25 and, accordingly, is eccentrically disposed with respect to the axis of the cylindrical pump housing 80. Pumping member 83 is provided with a pair of external circumferential grooves 84 and 85 that are utilized as ball races. Thus, groove 84 is filled with a plurality of ball bearing members 86 and groove 85 is similarly filled with ball bearings 87.

A pumping element comprising a sleeve 88 is rotatably mounted upon pumping member 83. In the illustrated construction, pumping element 38 is a cylindrical sleeve having two internal ball race grooves 91 and 92 for receiving ball bearings 87 and 36 respectively. Thus, the pumping element 88 is freely rotatable relative to pumping member 83.

In considering operation of the ink supply system of the present invention, it may first be assumed that the main ink reservoir 66 is filled, or substantially filled, with ink. When motor 33 is energized for a paper feed operation, shaft 17 is driven as described above, rotating the two sprockets 21 and 22 secured to the shaft and advancing the paper feed belts to move paper strip 47 through a distance suflicient to supply a new sheet of paper on platen 48. During this operation, shaft 25 is also rotated as a result of the rotational movement of pulleys 26 and 27 secured thereto and moved by the paper-advancing motion of the feed belts.

Rotation of shaft 25, during the paper feed operation, drives the shaft through one or more revolutions. As shaft 25 rotates, pump member 633 is caused to rotate correspondingly. At the start of the pumping movement, it may be assumed that pumping member 83 is in the position illustrated in FIGS. 6 and 7, constricting and closing tubes 68 and 73 at points 68A and 73A at the bottom of pump housing 81. Rotation of shaft 25 is in a clockwise direction, as indicated by arrow A.

. As the shaft starts to rotate, the corresponding rotation of pump member 33- and the eccentricity of the pump member with respect to the shaft cause the pump member to move away from the bottom portions dtiA and 73A of flexible ink tubes 63 and 73-. Further rotation of the pump member brings the external sleeve or pump element 88 into engagement with the flexible tubes at the top of pump housing 81. The tubes are squeezed together at the top, and the point of construction moves progressively'in a clockwise direction back to the position shown in the drawings. Consequently, a quantity of ink is trapped in the tubing and forced outwardly thereof as indicated by arrow B. In a given time interval, a predetermined quantity of ink is thus pumped through pump 80 depending only upon the size of the ink conduits, the proportions thereof engaged with the internal surface of pump housing 31, and the rotational speed of shaft 25. Thus, a predetermined quantity of ink is pumped from main reservoir 66 through an inlet line comprising tubing 68 and into the auxiliary ink reservoir 61.

When the recording apparatus is first placed in operation, it may be necessary to actuate pump 80 more than one time in order to fill auxiliary reservoir 61 up to the level of recirculation line intake '71. Once this has been accomplished, whenever the ink level exceeds the elevation of recirculation intake 71, the excess ink flows into the recirculation line and is pumped back to main reservoir 66, by pump 80, in the same manner as the ink is pumped to the auxiliary reservoir.

In the illustrated system, the auxiliary reservoir 61is made large enough to hold sufiicient ink for any expected record sheet disposed upon platen 48. In fact, the size of the auxiliary ink reservoir is made big enough to permit virtually solid coloring of a paper sheet having an area equal to that of the platen. Consequently, there is no need to replenish the ink supply in the course of a Writing operation. Instead, ink is fed by capillary action from reservoir 61 through the ink supply line 62-d4 to pen 41 during each recording operation.

Each time the paper is changed, however, a fresh supply of ink is pumped through reservoir 61, and any excess ink is returned to the main reservoir. Ordinarily, the quantity of ink pumped into reservoir 61 during the time that paper feed motor 33 is energized is substantially larger than the ink that has been used by the previous recording operation. Consequently, the ink circulates through the system on an intermittent basis, the limited supply in auxiliary reservoir 61 being continuously replaced, at least in part, by fresh ink from the main supply, with a part of the old ink being returned to the main reservoir. This makes it possible to maintain positive control of the quantity of ink available in reservoir 61. In addition to maintaining substantially constant quantity of ink in the auxiliary reservoir, the system provides for recirculation of the ink, on an intermittent basis, so that the ink in the auxiliary reservoir is always fresh. The recirculation action of the system is effective to prevent deterioration, by solidification or otherwise, of the ink in the auxiliary reservoir.

Pump Silas described hereinabove, is the principal operating component of the ink supply system, other than the reservoirs themselves. This simple and inexpensive pump provides a positive pumping action both in furnishing ink from the main reservoir tothe auxiliary reservoir and in pumping excess ink back to the main supply. The provision of a ball bearing mounting for the rotary sleeve 88 that engages the flexible tubing 68 and 73 minimizes the rubbing of the contact member of the pump on the flexible tubing. Thus, as the pump member 83 that is affixed to shaft 25 rotates, pump element 88 is permitted to rotate with respect thereto so that the pump element is not rubbed across the entire length of the flexible tubing within housing 81. Instead, a progressive squeeze action is achieved, on the flexible tubes, without substantial rubbing between the tubes and sleeves 88. Accordingly, the operational life of the pump is limited only by the stability of the flexible tubes extending therethrough and these tubes can be readily and inexpensively replaced when necessary. Replacement, under normal circumstances, can be deferred for quite long periods, particularly in view of the protection of the tubing against continual abrasion.

As described hereinabove, pump is actuated on an intermittent basis, being driven by shaft 25 each time motor 38 is energized to advance paper through recorder 10. This is the preferred drive arrangement for the pump, but others may also be employed. For example, a timing device and separate drive 38' for the pump could be utilized, quite independently of the paper feed (see FIG. 3), with operating results essentially similar to those described above. Thus, if the pump is energized during a Writing operation, the location of the overflow, recirculation intake 71, relative to vent 76 prevents pumping of an excessive quanity of ink into auxiliary reservoir 61. Moreover, the location of the inlet and outlet conduits within auxiliary reservoir 61 is such that pen operation is essentially the same regardless of whether pen 41 is disposed in vertical alignment, as shown in FIG. 4, or is located in substantially horizontal alignment. Under either circumstance, vent '76 is at an elevation above recirculation intake 71. The recirculation intake is at a higher elevation than the ink inlet 69, which is located above the pen supply line inlet 62. Hence, recorder 10 can be disposed at virtually any angle from horizontal to vertical without materially affecting the ink supply system operation, as long as the recorder is not turned over on its back.

Hence, while preferred embodiments of the invention have been described and illustrated, it is to be understood that they are capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, a movable support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the pen;

an ink supply line connecting said pen to said auxiliary reservoir; a main ink reservoir;

and means for maintaining a substantially constant supply of fresh ink in said auxiliary reservoir, said means including conduits interconnecting said reservoirs and an intermittently actuated pump for pumping ink between said reservoirs at predetermined spaced time intervals.

2. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, a movable support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at apredetermined elevation relative to the an ink supply line connecting said pen to said auxiliary reservoir;

a main ink reservoir;

ink conduit means, comprising an inlet line and a recirculation line, connecting the auxiliary reservoir to the main reservoir;

a pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir;

and means for intermittently actuating the pump to pump ink into said auxiliary reservoir and to pump excess ink back from said auxiliary reservoir through said recirculation line to said main reservoir, to maintain a substantially constant supply or fresh ink in said auxiliary reservoir.

3. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet of given surface area, a movable support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the pen, said auxiliary reservoir having a limited capacity approximately the quantity of ink required to effect a recording covering said surface area;

an ink supply line connecting said pen to said auxiliary reservoir;

a main ink reservoir having a capacity many times greater than that of said auxiliary reservoir;

ink conduit means, comprising an inlet line and a recirculation line, connecting the auxiliary reservoir to the main reservoir;

a dual-channel pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir;

and means for intermittently actuating the pump to pump ink into said auxiliary reservoir through one pump channel and through said inlet line, and to pump excess ink back from said auxiliary reservoir through the second pump channel and through said recirculation line to said main reservoir, to maintain a substantially constant supply of fresh ink in said auxiliary reservoir.

4. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, a movable support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the pen and immediately adjacent the pen;

an ink supply line connecting said pen to said auxiliary reservoir at a predetermined elevation therein;

a main ink reservoir;

ink conduit means, comprising an inlet line and a recirculation line, connecting the auxiliary reservoir to the main reservoir, said recirculation line having an intake opening substantially higher than said predetermined elevation;

a dual-channel pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir, with one pump channel connected in said inlet line and the other in said recirculation line;

and means for intermittently actuating the pump to pump ink through said inlet line into said auxiliary reservoir and to pump excess ink back from said auxiliary reservoir through said circulation line to said main reservoir, to maintain a substantially constant supply of fresh ink in said auxiliary reservoir.

5. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, sheet-feed means for replacing the record-receiving sheet on the recording base, means for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, including a pen support member, and a pen mounted on said support member, said ink supply system comprising: an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the first conduit means connecting said pen to said auxiliary reservoir;

a main ink supply reservoir;

ink conduit means, comprising an inlet line and a recirculation line, connecting the auxiliary reservoir to the main reservoir;

a pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir;

and means for actuating the pump during intervals in which the sheet-feed means is actuated and for maintaining the pump unactuated otherwise, said pump acting to pump ink into said auxiliary reservoir continuously during intervals in which said sheet-feed means is actuated and further acting to pump any excess ink back from said auxiliary reservoir to said main reservoir to maintain a substantially constant supply of fresh ink in said auxiliary reservoir.

6. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, sheet-feed means for replacing the record-receiving sheet on the recording base, means for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, including a pen support member, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member immediately adjacent the pen;

a pen supply line connecting said pen to said auxiliary reservoir, said pen supply line having an inlet opening at a predetermined elevation in said auxiliary reservoir;

a main ink reservoir;

ink conduit means, comprising an inlet line and a recirculating line, connecting the auxiliary reservoir to the main reservoir, said recirculation line having an intake opening in said auxiliary reservoir substantially higher than said pen supply line inlet opena pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir;

and means for actuating the pump during intervals in which the sheet-feed means is actuated and for maintaining the pump unactuated otherwise, said pump acting to pump ink into said auxiliary reservoir continuously during intervals in which said sheetfeed means is actuated and further acting to pump any excess ink, above the level of the inlet opening to said recirculation line, back from said auxiliary reservoir through said recirculation line to said main reservoir to maintain a substantially constant volume of fresh ink in said auxiliary reservoir.

7. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, a movable support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording base, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the P an ink supply line connecting said pen to said auxiliary reservoir;

a main ink reservoir;

ink conduit means, comprising an inlet line and a recirculation line, connecting the auxiliary reservoir to the main reservoir, said inlet and recirculation lines each including at least'an intermediate section a main ink supply reservoir; ink conduit means, comprising an inlet line and an outof flexible tubing;

a pump interposed in the ink conduit means between and means for intermittently actuating the pump to pump ink into said auxiliary reservoir and to pump excess ink back from said auxiliary reservoir through said recirculation line to said main reservoir, to maintain a substantially constant supply of fresh ink in said auxiliary reservoir.

let line, connecting the auxiliary reservoir to the main reservoir; and

a rotary dual-channel pump interposed in the ink conduit means between the main reservoir and the auxiliary reservoir and connected to said paper feed shaft for actuation only during intervals in which the sheetfeed means is actuated, said pump acting to pump ink into said auxiliary reservoir continuously during intervals in which said sheet-feed means is actuated and further acting to pump any excess ink back from said auxiliary reservoir to said main reservoir to maintain a substantially constant supply of fresh ink in said auxiliary reservoir.

References Cited by the Examiner 8. An ink supply system for a graphic communication recording station comprising a recording base for supporting a record-receiving sheet, sheet-feed means including a paper feed shaft for replacing the record-receiving sheet on the recording base, means including a pen support member for moving a pen across said base to record data on a record-receiving sheet disposed on the recording, and a pen mounted on said support member, said ink supply system comprising:

an auxiliary ink reservoir mounted on said support member at a predetermined elevation relative to the P first conduit means connecting said pen to said auxiliary 30 reservoir;

UNITED STATES PATENTS 1,635,977 7/27 Ranger 17896 2,583,535 1/52 Adler 178-19 2,621,249 12/52 Ress 178--18 2,649,503 8/53 Adler 178-18 2,679,807 6/54 Bruckmann 103-149 2,693,766 11/54 Seyler 103-149 2,727,802 12/55 Bowditch 346- 2,734,099 2/56 Cahoon et a1. 178-49 2,937,917 5/60 Anthony 346-139 3,054,109 9/62 Brown 346-117 3,116,964 1/64 Zenner 346-140 LEYLAND M. MARTIN, Primary Examiner, 

1. AN INK SUPPLY SYSTEM FOR A GRAPHIC COMMUNICATION RECORDING STATION COMPRISING A RECORDING BASE FOR SUPPORTING A RECORD-RECEIVING SHEET, A MOVABLE SUPPORT MEMBER FOR MOVING A PEN ACROSS SAID BASE TO RECORD DATA ON A RECODRD-RECEIVING SHEET DISPOSED ON THE RECORDING BASE, AND A PEN MOUNTED ON SAID SUPPORT MEMBER, SAID INK SUPPLY SYSTEM COMPRISING: AN AUXILARY INK RESERVOIR MOUNTED ON SAID SUPPORT MEMBER AT A PREDETERMINED ELEVATION RELATIVE TO THE PEN; AN INK SUPPLY LINE CONNECTING SAID PEN TO SAID AUXILIARY RESERVOIR; A MAIN INK RESERVOIR; AND MEANS FOR MAINTAINING A SUBSTANTIALLY CONSTANT SUPPLY OF FRESH INK IN SAID AUXILIARY RESERVOIR, SAID MEANS INCLUDING CONDUITS INTERCONNECTING SAID RESERVOIRS AND AN INTERMITTENTLY ACTUATED PUMP FOR PUMPING INK BETWEEN SAID RESERVOIRS AT PREDETERMINED SPACED TIME INTERVALS. 